Degradative pathways in cultured synovial fibroblasts: selective effects of pulsed electromagnetic fields

Pulsed Electromagnetic Field Inhibits Synovitis via Enhancing the Efferocytosis of Macrophages

Synovitis plays an important role in the pathogenesis of arthritis, which is closely related to the joint swell and pain of patients. The purpose of this study was to investigate the anti-inflammatory effects of pulsed electromagnetic fields (PEMF) on synovitis and its underlying mechanisms. Destabilization of the medial meniscus (DMM) model and air pouch inflammation model were established to induce synovitis in C57BL/6 mice. The mice were then treated by PEMF (pulse waveform, 1.5 mT, 75 Hz, 10% duty cycle). The synovitis scores as well as the levels of IL-1β and TNF-α suggested that PEMF reduced the severity of synovitis in vivo. Moreover, the proportion of neutrophils in the synovial-like layer was decreased, while the proportion of macrophages increased after PEMF treatment. In addition, the phagocytosis of apoptotic neutrophils by macrophages (efferocytosis) was enhanced by PEMF. Furthermore, the data from western blot assay showed that the phosphorylation of P38 was inhibited by PEMF. In conclusion, our current data show that PEMF noninvasively exhibits the anti-inflammatory effect on synovitis via upregulation of the efferocytosis in macrophages, which may be involved in the phosphorylation of P38.

Electromagnetic fields (EMFs) and adenosine receptors modulate prostaglandin E(2) and cytokine release in human osteoarthritic synovial fibroblasts

Synovial fibroblasts (SFs) contribute to the development of osteoarthritis (OA) by the secretion of a wide range of pro-inflammatory mediators, including cytokines and lipid mediators of inflammation. Previous studies suggest that electromagnetic fields (EMFs) may represent a potential therapeutic approach to limit cartilage degradation and control inflammation associated to OA, and that they may act through the adenosine pathway. Therefore, we investigated whether EMFs might modulate inflammatory activities of human SFs from OA patients (OASFs) treated with interleukin-1β (IL-1β), and the possible involvement of adenosine receptors (ARs) in mediating EMF effects. EMF exposure induced a selective increase in A(2A) and A(3) ARs. These increases were associated to changes in cAMP levels, indicating that ARs were functionally active also in EMF-exposed cells. Functional data obtained in the presence of selective A(2A) and A(3) adenosine agonists and antagonists showed that EMFs inhibit the release of prostaglandin E(2) (PGE(2)) and the proinflammatory cytokines interleukin-6 (IL-6) and interleukin-8 (IL-8), while stimulating the release of interleukin-10 (IL-10), an antinflammatory cytokine. These effects seem to be mediated by the EMF-induced upregulation of A(2A) and A(3) ARs. No effects of EMFs or ARs have been observed on matrix degrading enzyme production. In conclusion, this study shows that EMFs display anti-inflammatory effects in human OASFs, and that these EMF-induced effects are in part mediated by the adenosine pathway, specifically by the A(2A) and A(3) AR activation. Taken together, these results open new clinical perspectives to the control of inflammation associated to joint diseases.

Histopathological and ultrastructural studies on the effects of electromagnetic fields on the liver of preincubated white Leghorn chicken embryo

There are several reports indicating a linkage between exposures to 50-60 Hz electromagnetic fields and abnormalities in the early stages of embryonic development of chicken embryos. The present study was designed to demonstrate whether electromagnetic fields could be an environmental factor invoking histopathological and ultra-structural changes in livers of preincubated chicken embryos exposed to EMFs. Following other researchers and our previous results from different groups of Developmental Biology at the Animal Sciences, Faculty of Biological Sciences, Shahid-Beheshti University, effects of most effective intensities (1.33, 2.66, 5.52, and 7.32 mT) of electromagnetic fields (EMFs, 50 Hz ) on livers of pre-incubated white leghorn chicken embryos were investigated . 150 healthy, fresh, and fertilized eggs (55-65 gr) were divided into 6 groups of experimental(1-4, n = 30), control (n = 60), and sham (n = 50). Experimental eggs (inside coil) were exposed to 4 different intensities (1.33, 2.66, 5.52, and 7.32 mT). Sham groups were located inside same coil, with no exposure, for 24 h before incubation. Control, sham, and experimental groups (1-4) were then incubated in an incubator (38 +/- 0.5 degrees C, 60% humidity) for 17 days. At the end of this period, livers of experimental, sham, and control groups were processed for light and transmission electrom microscopes (TEM and SEM) studies. So, livers of 17-day old chicken embryos were removed by C-sections, fixed in formalin 10%, stained with H&E and reticulin, and studied under light microscope. Others were prepared for electron microscopes (TEM and SEM) investigations. Morphological observations indicated exencephalic embryos, embryos with asymmetrical faces, crossed beak, shorter upper beak, deformed hind limbs, gastroschesis, anophthalmia, and microphthalmia. H&E and reticulin stainings, TEMS, and SEMs studies indicated EMFs would create hepato-cytes with fibrotic bands, severe steatohepatitis, vacuolizations, swollen and extremely electron-dense mitochondria, reduced invisible cristae, crystalized mitochondria with degenerated cristae, myelin-like figures, macrophages engulfing adjacent cells, dentated nuclei, nuclei with irregular envelopes, degenerated hepatocytes, abnormal lipid accumulations, lipid droplets pushing hepatocytes' nuclei to the corner of the cells, abundant cellular infiltrations cellular infiltrations inside sinusoid and around central veins, disrupted reticulin plexus, and release of chromatin into cytosol,, with partially regular water layers. An elevated oxyradical generation and, subsequently, cell membrane disruptions were the reasons for electromagnetic fields inducing cell damages.

Effect of electromagnetic stimulation with different waveforms on cultured chick tendon fibroblasts

An energy efficient electromagnetic stimulator device for fracture healing was compared to a commercially available device in stimulating cell growth in tissue cultures. The energy efficient device, which conserves energy by using a bidirectional time-dependent magnetic wave form, and the commercially available stimulator, which uses a unidirectional time-dependent magnetic wave form, were tested on chick tendon fibroblasts in primary culture. Comparing non-stimulated control and cells electromagnetically stimulated with unidirectional and bidirectional waveforms showed that at the growth phase between days 2 and 3, both electrical stimulation techniques increased cell division as measured by DNA synthesis. When cells were dividing rapidly, collagen synthesis was reduced. When the cells reached the confluence there was no difference among the groups (control, unidirectionally stimulated, and bidirectionally stimulated) in terms of number of cells or collagen produced.

[The effect of static magnetic fields on prostaglandin synthesis in L-929 and 3T3 mouse fibroblasts. An in-vitro study]

The aim of this study was to examine the influence of static, inhomogeneous magnetic fields on prostaglandin synthesis in L-929 and 3T3 mouse fibroblasts. Two pairs of magnets, one CoSm and the other NdFeB, were attached 10 mm apart under the culture chamber. One pair was in the attracting position and the other in the repelling position. The maximum magnetic induction measured was 85 respectively 120 mT and the incubation time was 72 hours. Control groups consisted of untreated cells and cells under the influence of demagnetized magnets. The following measurements were taken: prostaglandin synthesis (PGE2), protein content (GP), and the number (Z) of cells (only L-929 mouse fibroblasts). The data were analyzed statistically using the Tukey test and the significance niveau was set at alpha = 0.05. The results using this method demonstrated that the measurable effects of in vitro treatment of mouse fibroblasts with static magnetic fields of varying induction did not significantly differ from the control groups. The sensitivity of our method was verified beforehand with a recombinant, human TNF alpha stimulated reference group.

Biological effects of weak electromagnetic fields from 0 Hz to 200 MHz: a survey of the literature with special emphasis on possible magnetic resonance effects

The literature on biological effects of weak electromagnetic fields of a frequency of 200 MHz or less is surveyed. The topic has been extraordinarily controversial, in part because of disputed assertions about a role for electromagnetic fields in carcinogenesis or production of abnormalities in growth and development. There is fairly widespread acceptance of certain beneficial effects, particularly the stimulation of healing. An increasing number of reports point to interactions between static magnetic fields and time-varying fields in the production of some effects. Safety implications are noted along with the hypothetical possibility of production of experimental artifacts by electromagnetic fields in MRS research.